Study On The Bromination Of Aromatic Ethers In Aqueous Solution

In this paper, 2-methylanisole, 3-methylanisole, 4-methylanisole, 2-chloroanisole 3-chloroanisole, 4-chloroanisole, 1-methoxynaphthalene, 2-methoxynaphthalene were synthesized and purified with simple methods, and the purity of which were also determined by GC.Sodium bromide reacted with sodium bromate in acidic medium (sulfuric acid) to give bromine in situ, which was then used as the source of bromine for the bromination of eleven aromatic ethers such as anisole etc, the use of bromine with high concentration and high toxicity was avoided in this method. After searching for a series of conditions such as the quantity of reactants, reaction time, temperature and co-solvent, the conditions of bromination for each aromatic ether were confirmed eventually and a green process for the synthesis of bromated aromatic ethers. In addition, the products were purified and also were characterized by GC.Compared with the reactions reported in literatures carried out in pure organic solvents, in this paper, the main solvent of each reaction was water, and certain co-solvents were also used with the advantages such as easy to purification, economy and environmental-friendly. In other hand, the bromine generated in situ by inorganic reaction was then used in organic reaction for the bromination of aromatic ethers, so, inorganic reaction and organic reaction were carried out in one pot simultaneously. In addition, with homogeneity and low concentration, the bromine generated in this method is favorable for the regioselectivity of the following bromination.In one word, this methodology has been demonstrated as an atom economic one with potential industrial value.